Kiln for the heat treatment of materials



Jan. 10, 1933. H. c, ERITH E'rAL KILN FOR THE HEAT TREATMENT 0F MATERIALS Filed July 7. 1931 2 Sheets-Sheet 1 H. C. ERITH ET AL KILN FOR THE HEAT TREATMENT 0F MATERlALs Filed July 7, 1951 2 Sheets-Sheet 2 Patented Jan. 10, 1933 littl'lll STATES PATENT QFFECE HENRY CHAELES ERI-TH, CF SUTTGN, AND RAYMOND CHARLES ERITH, OF LONDON COUNTY, ENGLAND KILN FOB, THE lEAT'TR-EATEENT OF I'JlATER-IALS Application led July 7, "i931, Serial No. 549,236, and in Great Britain March 26, 1931.

This invention relates to kilns for the heat treatment of materials, especially refractory materials, and refers more particularly to kilns for the manufacture of bricks and other like products, the chief object of the invention being to provide a continuous kiln wherein progressive travel of heat through successive chambers takes place, and wherein improved mechanical means are provided for handling, not only the material undergoing treatment, but also, if desired, all apparatus, appliances or materials required for manufacturing, heating or dealing with the same, whereby an important reduction in production costs is effected, and damage and loss to the product (hereinafter termed bricks) are minimized by eliminating all manual handling operations, except those of stacking the bricks, prior to drying and burning, and placing the burnt bricks on discharging conmanually.

In order to reduce the rehandling and wheeling operations, wit its consequent extra labour costl and liability to loss and damage to the product, it has been proposed to use portable brick presses running on wheels around a continuous kiln, so that bricks can be charged from the press to the kiln chambers, or moved therefrom (for eX- ample to railway wagons) through the same door opening, preferably by means of aportable roller conveyor. lt has been found, however, that the use of the same door opening for loading and for discharging a kiln-chamber makes such operations impracticable, as the gravity roller conveyors as well as the use of a railway track for both purposes necessarily obstructs the use of the railway siding.

lt has therefore beenproposed to construct i semi-continuous substantially U-shaped riln, and to run wheeled brick presses on railway tracks situated between the legshof the L?, so that the kiln chambers, other than those at the closed or radial end of the kiln, have separate opening for loading fresh bricks, which openings face the openings through which the burnt bricks are discharged, thus enabling portable gravity oonveyors to be used both for charging and dis` mally runs onto permanent sills or supports situated in front of each kiln chamber, where the actual pressing operation is carried on, the press being thereafter returned by means of the lifting jacks to the railway track.-

Apartfrom the delay and trouble involved and the fact thatA a gang of men are requiredy to carry on the iacking operation, the railway obstructs the corridor and interferes with other operations that must be carried on, while the use of sills for supporting the press in front of each kiln chamber is ren-A dered necessary.

According to one feature of the present invention, and instead of employing a brick press running on wheels on a railway track situated in a corridor between parallel rows of kiln chambers, we employ a travelling crane or cranes, or its or their equivalent, (preferably one or more cranes of the traversing type and running on rails or supports situated above and parallel to the corridor, and preferably power operated), for raising or lowering, and, when desired, transporting one or more brick presses above thefloor of the corridor situated between the parallel rows of kiln chambers. The press or presses is or are lowered by the travelling crane or cranes in front of any kiln chamber or chambers which is or are to be charged with bricks, and, after the charging operation has been completed, the press or presses is or are again raised by the travelling crane or cranes, and

iop

after transportation to its or their new position, the press or presses is or are lowered in front of other kiln chambers which are to be charged.

5 According to another feature of the present invention, the curved kiln chambers formerly situated at thc closed end of the previously proposed U-shaped arrangement of kiln chambers, are dispensed with, and

- two parallel rows of kiln chambers, situated on opposite sides of a central corridor which is open at both ends, are provided, so that an uninterrupted corridor or passage is provided between a pair of parallel rows of kiln clflambers from the inlet to the exit end there- According to another feature of the present invention, and in order that the heating medium ma travel progressively through @the entire kiln, underground flues are provided extending transversely of the kiln and situated both at the entrances and exit ends thereof, which underground llues interconneet with other underground llues running 29 parallel to and located beneath the two rows of kiln chambers. Progressive heat travel throu underground flues is thereby obtain so that ring-flow of the heating medium is maintained throughout the two au parallel rows of kilnchambers According to another feature of the present invention the axis of each of the separate kilnA chambers in the parallel rows thereof is situated at right angles to the axis of the central corridor, and each kiln chamber is 'ded with a separate door opening for the introduction of fresh bricks, which door is situatedin the corridor and faces a door at the opposite end of the kiln chamber lo through which the burnt bricks are discharged. Portable gravity conveyors may also bra-provided which are available both for charging or for discharging any of the kiln chambers. Consequently, all the kiln chambers can be stacked and unloaded under comfortable working conditions, with free passage of light and air across each kiln chambei According to another feature of the pressa ent invention an endless band conveyor is also provided, which conveyor extends from the grinding mills situated in front of the first pair of transversely arranged kiln chambers to a point situated beyond the last pair of transversely arran kiln chambers of the series, the said en less band conveyor being ada ted to receive raw material from the mil s' which grind the same and to feed and deect vthe same into the feed hopper or GU hoppers of the transportable brick press or pressesat any point in the central corridor situated between the parallel rows of kiln chambers. Adjustable deflectors, which may be operated from the floor of the corridor, U5 may also be provided, associated with the band conveyor, in order that the raw material may be deflected from the conveyor into one or more of the presses situated in the central corridor. At, or towards, the extreme 0r return end of the endless band conveyor, a deflector may also be provided which feeds the surplus material from the upper to the lower strand of the conveyor, so that it is again returned to the grinding mills.

According to a further feature of the prescnt invention, and in cases where a travelling crane or its equivalent is provided, together with brick making presses transportable along a central corridor situated between parallel rows of kiln chambers; as also an endless band conveyor for feeding raw material into the said presses, means are rovided, constituted, for example, by buc ets associated with the travelling crane, for transporting by means of the travelling crane, an emergency supply of raw material for charging the brick making presses, should the endless band conveyor break down or be stopped for any reason.

In order that the said invention may be clearly understood and readily carried into ell'ect the same will now be described more fully with reference to the accompanying drawings, which show a layout of a continuouskiln constructed according to one embodiment of the present invention. and in which,

Figure 1 is a partial plan view of the centre part of a continuous kiln, having a plurality of chambers, such chambers being arranged in two parallel rows, divided by a central corridor; provision being indicated for discharging to railway wagons; but alternatively barges or lorries can be used if desired.

Figure 2 is a sectional elevation on line 1--1 of Figure 1.

Figure 3 is a cross-section on line 2-2 of Figure 1.

Figure 4 is a section on the line 3 3 of Figure 1.

A is a continuous kiln having a plurality of chambers D located on opposite sides of a central corridor B, the chambers D being traversed in series and progressively by heat for driving off the moisture, then for heating up the bricks, then for burning bricks by combustion of fuel, the air for combustion being drawn through bricks in process of cooling, thus regenerating useful heat and minimizing the time required for cooling bricks prior to withdrawal.

B are the chimneys (or alternatively snction fans may be used) removing the products of combustion and also the moisture-laden air. C are the fines leading to the chimneys. and provided with dampers regulating the outflow from the various kiln chambers. E are openings whereby gases or air can travel through the partition walls of adjacent chambers, and F are roof-fines whereby gases or air can travel to any further chamber, cross-flues G being provided across the ends of the kiln A, so that gases or air reaching the end of arow of parallel chambers can flow onwards towards the other end of the other row.

H are mills for grinding the raw material, with elevators and screens with chutes for returning tailings to the mills, while delivering the ground material to the endless bandconveyor I which supplies the series of brick presses J, which are transportable so as to be operated adjacent to the loading doors K of any kiln-chamber.

The endles band-conveyor I is provided with a mixing trough L provided with mixing ploughs, whereby a thorough mixture is effected of the ground material from the various mills H; additional moisture can also be introduced to the trough L and diiii'used uniformly throughout the material. H are haulage wagons; H2 are hoppers; Ha are elevators, and H4 are screens with chutes H5 returning coarse material to the mills, while the fine material is delivered to the endless band-conveyor I which supplies the hoppers J of the various brick presses J in all operating positions; while in the event of any stoppage of the band-conveyor I the crane is employed to transport, as hereinafter explained, ground material to the various presses J.

M are movable deflector troughs, preferably operated by rods from the ground level, whereby the requisite supply of material is deflected to each of the presses J in operation; and a similar deiiector trough M at the far end of the conveyor returns any surplus material by the lower strand of the endless band-conveyor I to the grinding mills.

N is a travelling crane running on rails N2, provided with a traverser N and travelling the entire building, and provided with mea-ns for raising any press J from the permanent supports on which it operates, and transporting it to other permanent supports for operation when filling other kiln chambers.

O are pans or buckets, into which any waste material or damaged bricks are dropped from the presses for periodical transport to the hopper H2 when raised and transported by the crane N.

In the event of stoppage of the endless band-conveyor I, these buckets O are used for transport by the crane N of ground material from the mills H to the hoppers J of the presses J.

P are portable gravity-roller conveyors, in sections adapted for transport by the crane N, and such sections are assembled within the kiln chambers D. Alternatively, they may be employed to deliver freshly made bricks from a press to any point in the chamber where brick settcrs are open-stacking the bricks suitably for burning; or for delivering through the outlet doors Q, from any point in the kiln chamber and direct to railway wagons D2, lorries or barges, the burnt bricks as unloaded after burning and cooling. The crane N is also used to transport to the repair shops, any machines or components of mechanism which may require repair or renewal. rl`lie crane N can equally be used for a grab or other bucket O to transport the coal supply from railway wagon D to coal hoppers R- above the top level of the top-fired kiln A, coal being preferably dropped from such4 hoppers R to barrows which are tipped direct to the fire-hole stokers if used, or if mechanical firing is not adopted, the coal is wheeled and dropped at convenient points for the lire-holes S. In cases where top-firing is not practised, the coal can flow from hoppers R to low-level furnaces with or without mechanical stokers.

The kiln chambers are shown with arched roofs and arched door openings, but any type of suspended or supported flat roof may be used, either of a permanent or of a temporary type, with rectangular or other shapedy door opening. When flat roofs are employed they may consist of hollow blocks suspended to longitudinal girders hanging from transverse main girders, the hollow blocks forming ducts or lines, with communieating riser iiues in the partition walls, as also openings having removable Stoppers. In such cases, temporary partition walls of unburnt bricks adapted to deflect the gases from one chamber to another, in Zig-zag travel, may be used, together with hot air flues arranged in the upper part of the longitudinal walls of the kiln.

Provision can be made for gas or for oil firing, but in the embodiment of the in vention illustrated, the usual method of direct firing by means of small coal through fireholes in the arch or roof of the 'chambers under lire is shown. Positive mechanical stokers orfeeders (not illustrated) of known types, may be employed, driven in series by ratchet mechanism, such feeders being easily removed to any desired point of operation.

Mechanical fan draught can be used wholly or partially in substitution for chimney draught, if desired.

Direct electric drive is preferably used for all mechanism, including the haulage of raw material, the individual grinding mills, the endless band conveyor, the brick presses, the travelling crane, the feed mechanism for a group of mechanical coal feeders or stokers, and for any fans used for any purpose.

It will also be seen that by reason of the present invention all fuel can be mechanically transported to hoppers discharging to convenient points above the respective parallel rows of kiln chambers, by a grab or other bucket travelling down the central corridor on the travelling crane, which also has means for raising and transporting the various brick presses to any point of the corridor or to permanent supports for operation so as to supply any kiln-chamber. The crane may also be employed to transport the sectional gravity-roller conveyors for loading or for discharge of bricks, to any kiln-chamber; it is equal'iy used for transporting any machine parts requiring repair or renewal; also for transporting to the grinding mills tubs into which any Waste materials or defective bricks from the presses are dropped; and further, in die event of stoppage of the continuous band-conveyor which normally supplies ground material to the various presses, the crane een be employed to transport in tip-buckets a suitable supply of material from the mils to the hoppers of the brick presse-s, thus securing their uninterrupted operation even in such emergencies.

Both fuel and raw material, ground material, lfreshly-made or green bricks, and burnt bricks or other such products, are handled mechanically, with the necessary exception that'manual labour is needed for open-stacking the green bricks for burning, and also for unstacking bricks after burning and ceoling.

A very large reduction in capital costs and the coequent capital charges on the product is eected by simplifying the building work,

' and byintroducing simple and reliable mechanism; while provision is made for emergency operation in the event of the stoppage of any normally-employed mechanism, thus assuring continuity of operation. All transportation is effected in straight lines, i. e., either longitudinally or transversely, and the open central corridor provides a permanent support, to which a press can be instantly transported and clamped or bolted for operation.

We claim:

1. A continuous kiln having in combination a multiplicity of kiln chambers disposed contiguous to one another on opposite sides of a central corridor, a portable press, transporting means located above the floor level of the corridor for raising, lowering and transporting the press to any desired point in the corridor, an endless band conveyor extending longitudinally through the central corridor, grinding means situated at the front of the conveyor, said endless band conveyor being ada ted to receiveraw materials from thegrinding mills and to feed the same into the press at any point in the central corridor.

2. A continuous kiln having in combination a multiplicity of kiln chambers disposed contiguousto one another on opposite sides of a central corridor, a portable press, a movable 4crane rlocated above the floor level of the corridor for raising, lowering and transporting the press to any desired point in the corridor, an endless band conveyor extending longitudinally through the central corridor, grinding means situated at the front of theconveyor, said endless band conveyor being adapted to receive raw materials from the grinding mills and to feed the same into the press at any point in the central corridor.

3. A continuous kiln as claimed in claim 1, wherein adjustable deiectors are provided and associated with the band conveyor in order'that the raw material may be deflected from the conveyor into the portable press.

4. A continuous kiln as claimed in claim 1, wherein the inlet and outlet openings to each kiln chamber are disposed opposite to one another and at right angles to the axis of the central corridor, the corridor being c-pen at both ends, longitudinally located underground flues extending beneath the contiguous rows of kiln chambers, and transverse underground dues interconnecting the longitudinal fines and disposed beyond the kiln chambers at the exit and entry ends of the corridor so as to allow a ring-flow of the heating gases. 5. A continuous kiln as claimed in claim 1 in which a deflector is provided at the end of the endless band conveyor remote from the grinding mills for feeding surplus material fromthe upper to the lower strand of the conveyor so that'it is again returned to the grinding mills at the front end of the conveyor.

In testimony whereof We have aiiixed our signatures.

HENRY CHARLES ERITH. RAYMGND CHARLES ERITH. 

